LSS - Modelling cable in a channel

[sapayne]

I'm preparing an LSS that involves brake cables under tension. The metal cable itself holds tension, but the housing does not. The cable housing is acted on by outside forces (radial direction). I'm wondering how best to model the cables. Spring elements? Gap elements?

They need to have a prescribed stifness and support radial loads along the length of the cable. I thought about setting up a number of lines down the axis and defining them as gaps or springs, but wasn't sure how this would take radial loads or maintain the nodes at the centre of the housing channel.

Thanks,
Shannon

[AstroJohnPE]

Hi Shannon,

It might be helpful if you can attach a sketch of your model so that we understand the location of the cables relative to everything else.

Keep in mind that LSS (linear static stress) requires the model to be statically stable. So in most cases (if not all situations), you can use only have one truss/gap element to model the cable. You cannot break the cable into multiple elements to represent or calculate the catenary shape. You would need to use MES (Mechanical Event Simulation) to calculate that type of system.

[sapayne]

I've attached a image illustrating my prelimiary model setup. In this case I've modelled the cable as a solid body. The ends of the solid body cables are fixed and at the other end there are surface forces putting those cables in tension and two others creating torsion.

I would like to replace the solid cables with something less compuationally expensive.

Thanks,
Shannon.

[AstroJohnPE]

Beam elements are the only type of "line" element that will transmit a torque, so you essentially need to make the cable from beam elements.

[sapayne]

Thank you John, I appreciate the help.

To use beam elements I would suppress the solid and connect two nodes, on at either end of th cable, with a line? Or would it be more appropriate to make a large number of beam elements in the channel so that they could bow as a cable might?

In using this method, how to you ensure the beam stays in the center of the channel? Is that taken care of by setting the approptriate diameter in the element definition? I need to ensure that contact throughout the channel is modelled.

Thanks again,
Shannon